1. Field of the Invention
The present invention relates to a signal transmitting device, a signal transmitting method, a signal receiving device, and a signal receiving method for serially transmitting a video signal specified by a 3G-SDI format and a sound signal that synchronizes with the video signal.
2. Description of the Related Art
The development of an image receiving system and an imaging system for an ultra high definition video signal exceeding the present HD (High Definition) signal, which is a video signal (an image signal) having a one-frame size of 1920 samples×1080 lines, is under way. For example, a UHDTV (Ultra High Definition Television) standard, which is a broadcast system of the next generation having the number of pixels four times to sixteen times as larger as the present HD, is proposed in the ITU (International Telecommunication Union) and the SMPTE (Society of Motion Picture and Television Engineers) and standardized. Video signals of a video standard proposed in the ITU and the SMPTE are video signals of 3840 samples×2160 lines and 7680 samples×4320 lines twice and four times as large as 1920 samples×1080 lines.
In recent years, a standard for transmitting a signal of 1920 samples×1080 lines/60 P, which is a frame rate twice as high as 1920 samples×1080 lines/30 P (60I), and a high-resolution video such as a digital cinema using a 3G-SDI called SDI (Serial Digital Interface) of the third generation is proposed in SMPTE425M. The 3G-SDI Level A specifies 1080I/P transmitted by an HD-SDI. The 3G-SDI Level B is specified as a system for multiplexing two HD-SDIs. This is because a transmission rate in the 3G-SDI is twice as high as that in the HD-SDI. The number of multiplexes of audio data sampled at 48 kHz (audio data sampled at n kHz is hereinafter abbreviated as “n kHz sampling audio”) is maximum 16 channels per one channel of the HD-SDI.
JP-A-2005-328494 discloses a technique for serially transmitting a 3840×2160/30 P, 30/1.001 P/4:4:4:/12 bit signal, which is a kind of a 4 k×2 k signal (an ultrahigh resolution signal of 4 k samples×2 k lines), at a bit rate equal to or higher than 10 Gbps. [3840×2160/30 P] indicates [the number of pixels in the horizontal direction]×[the number of lines in the vertical direction]/[the number of frames per one second]. The same applies in the following explanation of this specification. [4:4:4] indicates a ratio of [red signal R: green signal G: blue signal B] in the case of a primary color signal transmission system and indicates a ratio of [luminance signal Y: first color difference signal Cb: second color difference signal Cr] in the case of a color difference signal transmission system.